what's "invisible user" mean?

What is an invisible user?

Can you explain more on where exactly you see that term used? I have an idea on what you are referring to, but would like to make sure

Savi

An "invisible user" is someone who has changed the settings in their profile to not be visible in the "Who's online" listing when they're logged on. Most of us don't do that, because it's nice to see who is logged on!

why do they do that? for privicy? is it the same thing as a hidden user on other forums?

Pretty much the same thing. I don't understand the reason, myself, but I guess some people really like privacy!

Also, what is the diference between flat and threaded posts?
I can't enter an anonomus username if I reply.

Flat and threaded are two different ways of looking at topics. Try clicking on it, and you'll see what it does. You can change back and forth any time you like.

Changing the username only works if you click on the "Reply" link. If you use the "Quick Reply" area, you don't have that option.

ok thanks. I didn't notice that.